IN A FIRST, A JAPANESE ASTRONAUT HAS TAKEN OVER COMMAND OF THE ISS. IN A HUGE BUT LITTLE KNOWN MILITARY LAB COMPLEX IN CENTRAL FLORIDA THE AIRFORCE IS MAKING SURE NUCLEAR WEAPONS ARE KEPT IN CHECK. THE AIRFORCE OPENED A NEW SET OF BUILDINGS TODAY. DAN BILLOW WENT FOR A RARE LOOK INSIDE. A LOOK AT THE CAT AND MOUSE GAME THAT PREVENTS NUCLEAR ARMAGEDDON. IN A ROOM CLEANER THAN A NASA SATELLITE BAY, TECHNICIANS TEST THE AIR BEFORE THEY LOOK FOR SAMPLES OF HIGHLY ENRICHED URANIUM. THE KIND USED IN NUCLEAR WEAPONS. URANIUM FOR PEACEFUL PURPOSES DOES NOT NEED TO BE ENRICHED TO THAT LEVEL. WELCOME TO THE NEW NEW $158 MILLION HEADQUARTERS OF THE AIRFORCE TECHNICAL APPLICATIONS CENTER. WHERE A THOUSAND PEOPLE QUIETLY WORK TO KEEP NUCLEAR WEAPONS IN CHECK. THE NEW BUILDING REPLACES THE 50'S ERA LANDMARK AT PATRICK AIRFORCE BASE ON A1A. A BUILDING ONE OF THE FIRST TO BE HARDENED AFTER 9/11 BECAUSE IT IS A PRIME TERRORIST TARGET. THE AIRFORCE HARDLY EVER LETS THE PUBLIC SEE WHAT THEY DO HERE. IT IS YOUR ONE CHANCE TO SEE WHAT HAPPENS INSIDE. IF THERE'S A NUCLEAR RELEASE ANYWHERE IN THE WORLD, A PLANE FLIES THROUGH THE AIR TO TAKE SAMPLES OF ANY RADIOACTIVE MATERIAL THAT MAY HAVE BEEN RELEASED. THOSE SAMPLES ARE BROUGHT RIGHT HERE. BY TESTING THE SAMPLES, SCIENTIST TZ KNOW IF NUCLEAR TREATYS ARE BEING VIOLATED. SEISMIC SENSORS AROUND THE WORLD TELL THEM WHETHER BANNED NUCLEAR TESTS ARE GOING ON. THE COLD WAR WAS QUIETLY FOUGHT AND WON HERE AND THIS IS WHERE THE PEACE WAS MONITORED. A MEMBER OF THE COMPREHENSIVE TEST BAN TREATY OFFICE IN VIENNA PUTS IT IN SIMPLE TERMS. IT IS MAKING THE WORLD SAFE AND SECURE. IN HERE, THE ACCOMPLISHMENTS OF THE WORKFORCE ARE OFTEN UNKNOWN BECAUSE THEY'RE SECRET. THEY KEEP TO THEIR MOTTO -- IN